- 您現在的位置：買賣IC網 > PDF目錄373931 > AD8042 (Analog Devices, Inc.) Dual 160 MHz Rail-to-Rail Amplifier PDF資料下載
參數資料
| 型號： | AD8042 |
| 廠商： | Analog Devices, Inc. |
| 英文描述： | Dual 160 MHz Rail-to-Rail Amplifier |
| 中文描述： | 雙160 MHz的軌到軌放大器 |
| 文件頁數： | 12/15頁 |
| 文件大小： | 181K |
| 代理商： | AD8042 |
AD8042
REV. A
–12–
+5V
0.1μF
10
m
F
8
3
2
R
F
1k
V
1000
m
F
0.1
m
F
R
T
75
V
75
V
COAX
R
L
75
V
V
OUT
R
G
1k
V
220
m
F
R
T
75
V
V
OUT
1000
m
F
0.1
m
F
4
6
5
1
7
R
F
1k
V
R
G
1k
V
220
m
F
10
m
F
4.99k
V
4.99k
V
75
V
10k
V
COMPOSITE
VIDEO
IN
R
L
75
V
Figure 36. Single Supply Composite Video Line Driver
Using AD8042
Signals of bounded peak-to-peak amplitude that vary in duty
cycle require larger dynamic swing capability than their peak-to-
peak amplitude after ac coupling. As a worst case, the dynamic
signal swing required will approach twice the peak-to-peak
value. The two bounding cases are for a duty cycle that is mostly
low, but occasionally goes high at a fraction of a percent duty
cycle and vice versa.
Composite video is not quite this demanding. One bounding
extreme is for a signal that is mostly black for an entire frame,
but has a white (full intensity), minimum width spike at least
once per frame.
The other extreme is for a video signal that is full white every-
where. The blanking intervals and sync tips of such a signal will
have negative going excursions in compliance with composite
video specifications. The combination of horizontal and vertical
blanking intervals limit such a signal to being at its highest level
(white) for only about 75% of the time.
As a result of the duty cycle variations between the two extremes
presented above, a 1 V p-p composite video signal that is multi-
plied by a gain of two requires about 3.2 V p-p of dynamic volt-
age swing at the output for an op amp to pass a composite video
signal of arbitrary duty cycle without distortion.
Some circuits use a sync tip clamp along with ac coupling to
hold the sync tips at a relatively constant level in order to lower
the amount of dynamic signal swing required. However, these
circuits can have artifacts like sync tip compression unless they
are driven by sources with very low output impedance.
The AD8042 not only has ample signal swing capability to
handle the dynamic range required without using a sync tip
clamp, but also has good video specifications like differential
gain and differential phase when buffering these signals in an
ac-coupled configuration.
To test this, the differential gain and differential phase were
measured for the AD8042 while the supplies were varied. As the
lower supply is raised to approach the video signal, the first
effect to be observed is that the sync tips become compressed
before the differential gain and differential phase are adversely
affected. Thus, there must be adequate swing in the negative
direction to pass the sync tips without compression.
As the upper supply is lowered to approach the video, the differ-
ential gain and differential phase were not significantly adversely
affected until the difference between the peak video output and
the supply reached 0.6 V. Thus, the highest video level should
be kept at least 0.6 V below the positive supply rail.
Taking the above into account, it was found that the optimal
point to bias the noninverting input is at 2.2 V dc. Operating at
this point, the worst case differential gain is measured at 0.06%
and the worst case differential phase is 0.06
°
.
The ac coupling capacitors used in the circuit at first glance
appear quite large. A composite video signal has a lower fre-
quency band edge of 30 Hz. The resistances at the various ac
coupling points—especially at the output—are quite small. In
order to minimize phase shifts and baseline tilt, the large value
capacitors are required. For video system performance that is
not to be of the highest quality, the value of these capacitors can
be reduced by a factor of up to five with only a slightly observ-
able change in the picture quality.
Single-Ended-to-Differential Driver
Using a cross-coupled single-ended-to-differential converter, the
AD8042 makes a good general purpose differential line driver.
This can be used for applications such as driving category 5
twisted pair wire which is becoming common for data communi-
cations in buildings. Figure 37 shows a configuration for a cir-
cuit that performs this function that can be used for video
transmission over a differential pair or various data communica-
tion purposes.
50m
AMP1
8
3
2
6
5
7
4
–5V
1
AD8042
100
V
0.1
m
F
10
m
F
60.4
V
60.4
V
1k
V
V
IN
49.9
V
R
IN
1k
V
R
A
R
A
1k
V
1k
V
1k
V
R
F
1k
V
121
V
R
B
R
B
0.1
m
F
10
m
F
V
OUT
AMP2
Figure 37. Single-Ended-to-Differential Twisted Pair Line
Driver
相關PDF資料 |
PDF描述 |
|---|---|
| AD8042AN | Dual 160 MHz Rail-to-Rail Amplifier |
| AD8042AR | Dual 160 MHz Rail-to-Rail Amplifier |
| AD8042AR-REEL | Dual 160 MHz Rail-to-Rail Amplifier |
| AD8042AR-REEL7 | Dual 160 MHz Rail-to-Rail Amplifier |
| AD8042ACHIPS | Dual 160 MHz Rail-to-Rail Amplifier |
相關代理商/技術參數 |
參數描述 |
|---|---|
| AD8042_06 | 制造商:AD 制造商全稱:Analog Devices 功能描述:Dual 160 MHz Rail-to-Rail Amplifier |
| AD8042_07 | 制造商:AD 制造商全稱:Analog Devices 功能描述:Dual 160 MHz Rail-to-Rail Amplifier |
| AD8042ACHIPS | 制造商:Analog Devices 功能描述: |
| AD8042AN | 功能描述:IC OPAMP VF R-R DUAL LP 8DIP RoHS:否 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標準包裝:73 系列:Over-The-Top® 放大器類型:通用 電路數:4 輸出類型:滿擺幅 轉換速率:0.07 V/µs 增益帶寬積:200kHz -3db帶寬:- 電流 - 輸入偏壓:1nA 電壓 - 輸入偏移:285µV 電流 - 電源:50µA 電流 - 輸出 / 通道:25mA 電壓 - 電源，單路/雙路(±):2 V ~ 44 V，±1 V ~ 22 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:16-WFDFN 裸露焊盤 供應商設備封裝:16-DFN-EP（5x3） 包裝:管件 |
| AD8042AR | 功能描述:IC OPAMP VF R-R DUAL LP 8SOIC RoHS:否 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標準包裝:50 系列:- 放大器類型:J-FET 電路數:2 輸出類型:- 轉換速率:13 V/µs 增益帶寬積:3MHz -3db帶寬:- 電流 - 輸入偏壓:65pA 電壓 - 輸入偏移:3000µV 電流 - 電源:1.4mA 電流 - 輸出 / 通道:- 電壓 - 電源，單路/雙路(±):7 V ~ 36 V，±3.5 V ~ 18 V 工作溫度:-40°C ~ 85°C 安裝類型:通孔 封裝/外殼:8-DIP（0.300"，7.62mm） 供應商設備封裝:8-PDIP 包裝:管件 |
發布緊急采購，3分鐘左右您將得到回復。